APPRAISE-AEROSOL

Principal Investigator: Prof Ken Carslaw 
Co-Investigator: Prof Martyn Chipperfield
Sponsor: NERC

Start Date: 1st October 2006
End Date:  30 September 2009

Value to Leeds: £243,361.60

Institute: Institute for Climate and Atmospheric Science

Abstract

This proposal will develop, document and make available to the UK community a package of closely related global models that can be used to test processes, develop state-of-the-art schemes for the UM, and be used flexibly in support of field campaigns.

1. A global model of aerosol microphysics and chemistry within the TOMCAT CTM (GLOMAP-tomcat). Specifications: Offline chemical transport model driven by ECMWF winds; multi-stage grid nesting down to 10x10 km; bin-resolved particle size distribution, multicomponent internal mixtures, thermodynamic treatment of particle hygroscopicity (for inorganic and organic mixtures); particle types to include mixed inorganic (H+, NH4+, SO42-, NO3-), industrial and biomass soot, organic primary carbon, secondary organic carbon, dust, sea spray; processes to include nucleation, condensation, coagulation, deposition, wet removal cloud processing (aqueous chemistry).
2. The UKCA model aerosol scheme implemented in the TOMCAT CTM (UKCA-tomcat). To include the same emissions and processes as GLOMAP-tomcat but with a particle size distribution based on a number of log-normal modes. A core version of UKCA-tomcat identical to that implemented in the UM will be retained as more advanced versions are developed. Comparison of the two models against observations within tomcat will enable maximization of the realism of the less CPU-intensive UKCA scheme for the UM.